Furnace for heat treating wire



April 14, 1942. c. D. JOHNSON FURNAGE FOR HEAT TREATING WIRE Filed Sept. 23, 1941 o OJ lnvenor` @hadas Ddohnson Petentea Ape. 14, 1942 FURNACE FOR HEAT TREATING WIRE Charles D. Johnson, Worcester, Mass., assignor to Johnson Worcester, setts teel and Wire Company, Inc., ass., a corporation of Massachue Application september 23, 1941, serial-No. 411,979

(c1. 26e-s) 1 Claim.

This invention relates to furnace for heat treating wire and particularly to a novel means for sealing the delivery end of the furnace so -as 'to prevent the heated wire which is delivered from the furnace from contact `with air until after the wire has cooled to a point where contact with the air will not produce any deleterious oxidizing eiect.

In order to give an understanding of the invention, I have illustrated a selected embodiment thereof in the drawing which will now-be described after which the novel features will be pointed out in the claim.

Fig. l is a view partly in section illustrating a furnace for heat treating wire embodying my invention.

Fig. 2 is a section on line 2-2 Fig. 1.

In the drawing, l indicates a furnace of any suitable type by which the wire 2 is subjected to the heat treatment, the furnace being of that known type which is provided with a plurality of tubes 3 which extend through the furnace from one end to the other thereof and through which the wire, 2 to be heat treated is passed. The furnace may be equipped with any number of these tubes 3. The tubes 3 are filled with a nonoxidizing gas so that during the heating of'the wire it is in a non-oxidizing atmosphere. For this purpose each tube 3 has an inlet pipe 4 connected thereto through which the non- -oxidizing gas is delivered to the tube. The deof vthis gas will escape from the entering end B of the tube 3, while the remainder of the gas flows through the tube 3 into the chamber G and escapes through the discharge pipe 1. 'I'he gas escaping from the inlet end 8 of each pipe is ignited to produce a flame 9, and similarly any gas escaping from the discharge pipe 1 is-ignited to produce a flame I0.

Associated with the chamber 6 is an oil-containing pan II which contains a body of oil I2. The dividing wall I3 between the chamber 6 and the oil pan is provided with apertures I4 situated in alignment with the various tubes 3, said apertures being below the level of thel oil in said pan. The wire 2 which is delivered from each tube 3 passes through the4 chamber 6- and then through the Icorresponding aperture It into thebody of oil I2 in the oil pan II.

Since each tube 3 and the upper portion of the chamber 6 is filled with the non-oxidizing gas and since the oil level in the pan vlI is above the apertures I4, each strand of wire is 'sealed against contact with the air until it is withdrawn from the oil bath I2. By the time the wire emerges from the oil bath it has been suiiiciently cooled so that it will not become oxidiited by contact with the air.

The oil level in the pan II is maintained at a v point above the apertures i4 thereby preventing any air from entering the chamber S. There will, therefore, be a constant ilow of oil through A each aperture lli into the chamber as shown at l5, but means are provided for maintaining the proper oil level in the pan I I ai; a'point above the apertures Id. f' A Each end wall of the chamber 6 is formed in two sections, a lower section 28 and an upper section 25. These two sections of each end wall are oiset from each other, each lower section 28 being on the outside of the corresponding uppersection 25. The upper edge 29 of eachlower wall section' 28 is situated below the tubes 3, andthe lower edge 30 of each 'upper wall section 25 extends below the upper edge 29 of each lower sections will be submerged in the voil and the space I8 between the upper edge portion of each wall section and the lower edge portion of the corresponding upper wall section will constitute a spillway through which the surplus oil is discharged lfrom the chamber 6, as shown at 20. into a collecting pan or vat I9. 2| indicates a suitable pump having its inlet 22 submerged in the oil 23 which collects in the tank I9 and having its outlet 24 extending through the bottom of the oil pan Il. This pump serves to e pump oil from the tank i9 into the pan IIl thereby maintaining the proper oil level in said pan. Since the lower edges 30 of the upper wail sections are submerged in the bath 26 of oil, the non-oxidizing gas which ows into the upper portion of the chamber 6 between] the upper wall sections 25 becomes trapped therein and can only escape through the outlet pipe 1. These upper wall sections 2l thus cooperate with the oil bath to forma seal which prevents air from entering the lchamber i through the spillway II.

In the operation of the device. the wire to be treated is delivered to each tube 3 through its entering end I and as the wire passes through the heated tube 43 it receives its heat treatment in a non-oxidizing atmosphere. As the wire emerges from each tube 3, it passes through the upper portion of the chamber i, which isalso illled lwith non-oxidizing gas, and thence it passes through the opening il into the oil bath I2 which serves as a cooling oath thereby to cool the wire to a point where it will not be oxidized by contact with the air. Inasmuch as the oil level in the pan is maintained above the apertures Il, said oil serves to seal the apertures against the admission of air and hence each wire can have no contact with the air until it has been delivered from the oil bath l2.

A furnace for heat treating wire comprising a furnace element having a tube extending therethrough through which the wire to be treated is passed, a sealing chamber with which the delivery end of the tube communicates, one side wall o i' said chamber being made with an upper section and a lower section which are offset with respect to each other. said lower section being situated outside of the upper section and the top edge of the lower section being located below the delivery end of said tube but abovethe lower edge of the upper section, an oilcontalning pan, one end wall of which is formedby the side wail of the chamber opposite to that through which said tube enters, said combined chamber side wall and pan end wall having an aperture in line with said tube and .through which the wire passes, ,fme'ans to maintain the oil in the oil pan at a level above said aperture, whereby the oil draining into said chamber through said aperture maintains an oil level in the chamber which is determined by the upper edge of the lower wall section and is above the lower edge of the upper wall section, the lower edge of the upper wall section being submerged in the oil in the chamber, the space between the therein lled with non-oxidizing gas, said submerged edge of the upper wall section in co-` operation with the oil forming a seal for said chamber.

CHARLES D. JOHNSON. 

